I've been on it for 2 years, off and on. I went from a 30 mg dose to a 50 & purposely took two of the 50 to see what it would do & convinced my dr that 100 was good for me. I'm 14 girl & I weighed 140 at the time. It made me stutter more than I usually do & made my brain go so fast that I couldn't remember anything. I switched to Focalin & it sucked then Adderall which was OK but I wanted to go back to Vyvanse & try lower dose bc I knew 100 was too much and he conplied now I'm on 70 & I have never been happier. (wrong doses have horrible effects I've been there!!) Vyvanse by far is the best medication I've tried. I struggle with bad depression and I don't tell my doctor about it but I know I have it. Thinking about suicide all the time the only string that was still attached was the fact I'd hurt my family and my dog who's my best friend would be put down because I'm her everything and she wouldn't eat. I have attempted suicide. But now. Now I'm on 70 and I am just so happy. I'm motivated. I'm optimistic. I care about other people. I'm a really good person now. The downside is I occasionally get dry mouth resulting in bad breath. I don't lose weight from it anymore but it makes me so motivated. I see things in a much better way I hated life b4, i was always mad. Definitely recommend. If you think you are on a wrong dose talk to your doctor right away. This is a stimulant. This is a drug to temporarily change your brain's function and it's nothing to joke about or put off. Don't let yourself put it off.